1. Field of the Invention
The inventive concept relates to an arbitration circuit and a display driver integrated circuit, and more particularly, to an arbitration circuit to arbitrate a conflict between a read/write command and a scan command and a display driver integrated circuit including the arbitration circuit.
2. Description of the Related Art
In general, display devices in laptop computers and monitors are mainly liquid crystal devices (LCDs). An LCD includes a panel for forming an image, wherein the panel includes a plurality of pixels. The plurality of pixels are formed in an area where a plurality of scan lines that transmit gate selection signals cross a plurality of data lines that transmit gray scale data.
Display driver integrated circuits, which are used to drive display devices such as LCDs, may be a scan driving unit and a source driving unit integrated on one chip, wherein the scan driving unit is used to drive the plurality of scan lines and the source driving unit is used to drive the plurality of data lines. Also, small-sized display devices, such as included in small-sized PCs and mobile phones, may include a panel module for representing an image and a driving circuit for driving the panel included in the panel module.
In general, a display driver integrated circuit, in which a scan driving unit and a source driving unit are integrated, includes a memory for storing frame data. The display driver integrated circuit writes data into the memory, reads data from the memory, or scans data stored in the memory to transmit the scanned data to a panel by interfacing with an external microprocessor unit. In general, bit lines for data transferring during reading/writing in the memory and bit lines during scanning in the memory are shared with each other and thus when a read/write command and a scan command are provided at the same time, data may collide in the bit lines and thus a memory failure may occur.
Accordingly, in order to prevent a memory failure when a read/write command and a scan command are provided at the same time, in general, a read/write section and a scan section are separately secured and reading/writing and scanning are performed in corresponding sections. However, in the above method, even if a scan command is not actually provided, reading/writing may not be performed during a section secured for scanning and thus reading/writing speed may be decreased. Also, when a read/write command and a scan command overlap, a predetermined delaying operation for signals is performed and then the commands are executed in corresponding sections. However, the predetermined delaying operation is significantly affected by a change in pressure, voltage, and temperature (PVT) and thus is hard to control.